如何在不选择ROI的情况下使用OPENCV跟踪参数

Question

有人可以告诉我我应该将哪个第二个参数传递给 tracker.init((在检测行人后？在Internet中只有已选择ROI的参数。我尝试通过变量 rects ，但是它给了我一个错误

import numpy as np
import cv2
import sys
from imutils.object_detection import non_max_suppression
cap = cv2.VideoCapture("video.mp4")
hog_descriptor = cv2.HOGDescriptor()
hog_descriptor.setSVMDetector(cv2.HOGDescriptor_getDefaultPeopleDetector())
tracker = cv2.TrackerKCF_create()
ret, frame = cap.read()
while (1):
    ret, frame = cap.read()
    (rects, weights) = hog_descriptor.detectMultiScale(frame, winStride=(16, 16),
                                                       padding=(8, 8), scale=1.05)


    rects = np.array([[x, y, x + w, y + h] for (x, y, w, h) in rects])
    pick = non_max_suppression(rects, probs=None, overlapThresh=0.65)
    for (xA, yA, xB, yB) in rects:
        cv2.rectangle(frame, (xA, yA), (xB, yB), (0, 255, 0), 2)
    ret = tracker.init(frame)
    ret, = tracker.update(frame)
cv2.imshow("video", frame)
if cv2.waitKey(1) == 27:
    break
cap.release()
cv2.destroyAllWindows()

Answer 1

根据OPENCV示例代码https://github.com/opencv/opencv_contrib/blob/master/master/modules/modules/tracking/samples/samples/tracker.py，tracker.init的第二个参数。方框：

cv.namedWindow("tracking")
camera = cv.VideoCapture(sys.argv[1])
ok, image=camera.read()
...
bbox = cv.selectROI("tracking", image)
tracker = cv.TrackerMIL_create()
...
ok = tracker.init(image, bbox)

所以，如果要使用检测到的行人作为ROI，则应使用：

bbox = rects[index]
tracker.init(image, bbox)

索引是您要跟踪的检测到的行人数量